Modbus RTU BRX Do-More Master to Click Slave PLC

Recently I was asked to demonstrate communication between a BRX PLC and Click PLC using Modbus RTU. Both PLCs are available from automation direct com. Modbus serial communication (Modbus RTU) is a standard protocol used in many automation devices. It works on a Master / Slave configuration. You can have only one master per network on Modbus RTU (Remote Terminal Unit). A maximum of 32 devices (Nodes) on the network can communicate to the master. A review of the Modbus RTU protocol (RTU frames) can be seen at the following URL.
https://www.rtaautomation.com/technologies/modbus-rtu/
Using the BRX PLC as a Master, we will be communicating to the Click PLC (Slave). Our example will read 10 registers from the Click PLC and write 10 registers from the BRX PLC. Let's get started!

More information can be obtained at our website. This includes all of the links mentioned in this video.
https://accautomation.ca/modbus-rtu-brx-plc-master-to-click-plc-slave-communication

00:00 Modbus RTU BRX Do-More Master to Click Slave PLC
00:24 Overview of Communication - Modbus
01:40 Modbus RTU (RS485) Wiring
02:16 Click PLC Setup and Program for Modbus RTU Slave Unit
03:21 BRX Do-More PLC Setup and Program for Modbus RTU Master Unit
07:45 Running the programs and testing communication

This post is part of our BRX Series PLC. Here are some of the topics that we have already covered in this series.
System Hardware
https://accautomation.ca/brx-plc-system-hardware
System Hardware Video
https://youtu.be/wSYgY09VYeA
Unboxing Video
https://youtu.be/-Tf8m3BqzPo
Installing the Software
https://accautomation.ca/brx-plc-installing-the-software
Installing the Software Video
https://youtu.be/iFI1ebP8Zkk
Establishing Communication
https://accautomation.ca/brx-plc-establishing-communication
Establishing Communication Video
https://youtu.be/shU5g8MA8VM
Updating Firmware Video
https://youtu.be/gsfcGGK4-Sk
Numbering Systems and Addressing
https://accautomation.ca/brx-plc-numbering-systems-and-addressing
Numbering Systems and Addressing Video
https://youtu.be/-GiKnIDycKY
First Program
https://accautomation.ca/brx-plc-first-program
First Program Video
https://youtu.be/ANSNhdlm_Ao
Monitoring and Testing the Program
https://accautomation.ca/brx-plc-monitoring-and-testing-the-program
Monitoring and Testing the Program Video
https://youtu.be/gv3d0vozxac
Online Editing and Debug Mode
https://accautomation.ca/brx-plc-online-editing-and-debug-mode
Online Editing and Debug Mode Video
https://youtu.be/77pemu3zXrE
Timers
https://accautomation.ca/brx-plc-timers
Timers Video
https://youtu.be/0qU9kgunPi4
Counters
https://accautomation.ca/brx-plc-counters
Counters Video
https://youtu.be/k84VQy8ifgg
High-Speed IO
https://accautomation.ca/brx-plc-high-speed-io
High-Speed IO Video
https://youtu.be/6B5hp_Ri0Ls

There are several reasons why we are using the BRX Series Controller. Here are just a few.
- Standalone PLC with built-in I/O
- Built-in Data Logging
- Communication ability - Ethernet Port, RS232, RS485, USB - support for protocols such as Modbus RTU, Modbus TCP, ASCII, K-sequence (DirectLOGIC users), Custom Protocols (ASCII over serial, TCP or UDP over Ethernet)
- Built-in Analog input and output
- Integrated motion control
- High-speed counters
- Powerful instruction set (Video of Instructions in software)
- Ability to expand the system with a variety of modules
- Part of the Do-More series of PLCs which use the same free software. (Do-More Designer)
- Integrated simulator in the software capable of external communications for testing

The BRX series of programmable logic controllers consist of four different units. They differ depending on the Inputs and Outputs built into the unit and if it has an ethernet port.
No I/O Micro PLC unit – (BX ME)
10 Point Micro PLC unit – (BX 10/10E)
18 Point Micro PLC unit - (BX 18/18E)
36 Point Micro PLC unit - (BX 36/36E)
These CPUs (Central Processing Units) are also known as MPU (Multi-Processing Units) because of their communication capabilities.

https://www.accautomation.ca